Read an exclusive excerpt from Sitcom: A History in 24 Episodes from I Love Lucy to Community, out now from Chicago Review Press.

Curb Your Enthusiasm was devoted to the demolishing of icons, to finding the most awkward, unpleasant topic imaginable and luxuriating in squirming — both from within the show and for those of us following along at home. Impending terrorist attack: Who should be tipped off in advance? Sex offender moves to the neighborhood? Invite him over for the Passover Seder! Larry David, over the course of eight seasons of rancorous badinage, poses as an incest survivor, is arrested for stealing forks from a restaurant, recommends a prostitute to the board members at a stuffy country club, informs the audience at a bat mitzvah about the tickle in his anus, and subtly suggests to his wife that, in the event of said terrorist attack, it’s “a little ... selfish” to not let him abscond alone.

Curb Your Enthusiasm served as the inspiration for a new wave of series — mostly on the guy-friendly cable channel FX — about similarly incorrigible men and their antics. Emily Nussbaum of The New Yorkerreferred to them as “dirtbag sitcoms,” “crass, confident comedies that feature idiotic characters but are not themselves idiotic.”

The heroes of It’s Always Sunny in Philadelphia or The League are like a Petri dish of Larry Davids, divided and regrown until reaching critical mass. The League, ostensibly about competitors in a fantasy football league, rapidly slides away from its who-are-you-starting-Sunday trash talk toward an all-purpose array of David-esque antics. And It’s Always Sunny begins where Curb leaves off, with each episode a Swiftian mock proposal, acted out and dramatized by its socially inept, intellectually stunted characters. It’s Always Sunny’s ragged camerawork and deliberately awkward blocking only add to the show’s subliminal suggestion that this is the work of gifted amateurs, that the polished professionalism of the sitcom has broken down by the side of the road, replaced by this jury-rigged jalopy of mismatched tones and styles.

The same is often true of Curb’s foremost descendant and the inheritor of its mantle of socially maladjusted middle-aged male heroism. Louie is written, directed and edited by stand-up comedian Louis C. K., whom FX provided with a minuscule budget and complete creative freedom. Unlike most sitcoms, Louie actually looks good — a product of Paul Koestner’s sterling cinematography — but the sense of amateurism, of television created by someone who does not actually belong on television, lingers.

Louie’s template remains generally the same from week to week: an extended opening stand-up routine à la Seinfeld, followed by one or two longer sketches. Like Larry David, Louis C. K. is a teller of uncomfortable truths, his best jokes revolving around his mixed feelings about his children, his body’s middle-aged failings and encounters with strangers. The sketches that follow are all over the map, from a visit to an elderly racist aunt to a strained meeting with fellow comic Dane Cook, whom C. K. had accused — in real life — of stealing other comics’ jokes.

Louis C. K., like Larry, is never allowed to skate on his misdemeanors. Approaching Cook for tickets for his daughter in the episode “Oh, Louie/Tickets,” he is made to squirm for his purported violations of the comedians’ code. Out on a date with an attractive woman in the remarkable episode “Bully,” he is humiliated at painfully extended length by an obnoxious teenager and secretly follows him back to his parents’ home in the suburbs. Louie is a deliciously awkward show, touching on all the inexplicable weirdness and brutal bittersweetness of life.

Louie is also a primer course in comedy; this is stand-up with footnotes appended. Has there ever been another show on television that turned over five minutes to a gay comic explaining the etymology of the word “faggot?” (“So what you’re saying is gay people are a good alternative-fuel source?” Louie asks, in wise-guy fashion.) Louie is forever explaining the nature of comedy to others: onstage hecklers, soldiers in Afghanistan, his kids.

Louie is also not entirely above the lowest common denominator; it is perfectly content to end an episode about Louie’s pregnant sister experiencing a medical emergency with her letting out a long, honking fart of relief. But C. K. is not satisfied with replicating the same comedian-gone-sitcom playbook. He reaches, with deliberate, impeccable awkwardness, for something deeper and more discomfiting than what television normally offers, like a show whose goal is to recreate, week after week, that indescribable jumble of laughter and half-buried sentiment Curb occasionally strives for.

There are flashback episodes about Louie’s tormented Catholic youth, and in the remarkable “Duckling,” which barely skirts the edge of cheap sentiment, C. K.’s daughter smuggles a tiny duck into his suitcase for a USO trip to Afghanistan. (“Holy shit on the tits of a dog,” he exclaims when he discovers the duckling.) C. K. is awkward even in a war zone. The entertainers’ helicopter makes a forced landing in uncertain territory, and the group comes face-to-face with a group of armed Afghans. The tense standoff is only broken when the duckling hops out of his backpack, and C. K., chasing after it, tumbles into a ditch. He shames himself and makes us laugh. And in so doing, our presentiments of death are pushed off, delayed for another day.

Louie, unlike many of its contemporaries at the cutting edge of the 21st century sitcom, is unafraid of approaching sentimentality in the name of transcendent emotion. Louie heads toward the helicopter taking him to safety, turns and hands the duckling to an Afghan girl. Even “Bully” ends not with the comeuppance of the obnoxious adolescent but with Louie commiserating with his tormentor’s father over the difficulty of raising children. Curb’s carnival music is replaced by a soundtrack of mournful jazz, ideal for the bittersweet dolefulness of a show about romantic failure and the onset of middle age.

In its best moments, Louie strives for a perverse kind of grace native to Curb, in which the show provides privileged moments of the sort Seinfeld — of the “no hugging, no learning” lack of sentimentality — would never have favored.

A carefully curated tour through TV comedy series, Sitcom: A History in 24 Episodes From I Love Lucy to Communitysurveys the genealogy of the form, the larger trends in its history, the best of what the genre has accomplished, and the most standard of its works. From I Love Lucy, The Phil Silvers Show and M*A*S*H to Taxi, The Larry Sanders Show and 30 Rock, this guide presents the sitcom as a capsule version of the 20th century arts — realism giving way to modernism and then to postmodernism, all between the hours of 8 and 10 P.M. on weeknights. Each chapter springs from an individual representative entity, including The Simpsons' "22 Short Films About Springfield," The Mary Tyler Moore Show's "Chuckles Bites the Dust," Seinfeld's "The Pitch" and Freaks and Geeks' "Dead Dogs and Gym Teachers," where Martin Starr's nerdy Bill takes comfort in — what else — the pleasures of laughing at TV.

Author Saul Austerlitz’s work has been published in The New York Times, The Los Angeles Times, The Boston Globe, The New Republic, Slate, The Village Voice and other publications. Follow him on Twitter: @saulausterlitz